椎管内血管脂肪瘤的MRI表现

Analysis of MRI findings of spinal angiolipoma

目的:分析椎管内血管脂肪瘤的MRI影像特点。方法 :收集我院手术病理证实的椎管内血管脂肪瘤8例,对其术前MRI影像进行回顾性分析。结果:8例椎管内血管脂肪瘤中,术后证实6例位于胸腰段硬膜外,1例位于胸腰段脊髓内,1例位于腰骶段髓外硬膜下;MRI术前定位准确8例,定性准确5例,另外3例定性为良性肿瘤。硬膜外病灶呈梭形压迫硬膜,椎管狭窄,于蛛网膜下腔与肿瘤间显示受压线样硬膜影,部分椎管内外生长病灶呈哑铃型伴椎间孔扩大,周围骨质无破坏;脊髓内病灶呈椭圆形,两端脊髓呈杯口状改变;硬膜下病灶呈新月形于硬膜下生长,硬膜无受压改变,椎管明显狭窄。病灶在T1WI、T2WI上均以等高信号为主,T2WI压脂后7例病灶信号增高,仅1例脊髓内病灶压脂后信号明显降低;增强后4例表现为轻度强化,3例中度强化,1例明显强化,6例强化均匀,2例强化不均匀。结论:椎管内血管脂肪瘤多发生于硬膜外,少数发生于脊髓内及硬膜下,本研究中有1例患者病灶位于硬膜下。MRI能清楚显示血管脂肪瘤的大小、形态、信号特点及其与椎管邻近结构的关系,具有准确定位及定性诊断价值。

Objective： To investigate the MRI features of spinal angiolioma. Methods： The MRI features of 8 surgically proved cases of spinal angiolipoma were analyzed retrospectively. Results： Six of the 8 cases of spinal angiolipoma were spinal epidural angiolipoma, 1 case was intramedullary angiolipoma, and 1 case was intradural extra-medullary angiolipoma. The accuracy of MRI for diagnosing the location of angiolipoma was 100%. Five cases were diagnosed as angiolipoma and 3 cases were diagnosed as benign tumor. Spinal epidural angiolipoma was presented as shuttle in shape, some cases locating at intervertebral foramens were dumb-bell in shape and adjacent intervertebral foramens were enlarged. The compressed dura mater appeared as linear structures with low signal intensity on MR images obtained with all sequences.The cavitas subarachnoidealis was narrow on affected level. The intramedullary angiolipoma was presented as oval structure and both ends of the spinal cord were cup mouth in shape. The intradural extra-medullary angiolipoma shaped like a crescent, the dura mater was not compressed but the cavitas subarachnoidealis was narrow. The MRI signals： isointense or hyperintense signals on T1 WI and T2 WI, 7 caseshad signals increased and one decreased on STIR; while 4 cases showed mild contrast enhancement, 3 cases had moderate enhancement, 1 case had intense enhancement on enhanced MRI; the intense was even in 6 cases and uneven in 2 cases. Conclusions： Spinal angiolipoma is mostly extradural, intramedullary and intradural extra-medullary are rare. The size, morphology, MRI signal of angiolipoma and the association with adjacent structure can be clearly displayed on MRI. MRI has good diagnostic value for the location and identification of angiolipoma.